The Daedalus Starship

written by Alan Bellows

The Daedalus Starship

Article #234 • written by Alan Bellows

In the winter of 1973, the men and women of the British Interplanetary Society convened in London to engage in some lively interstellar discourse. The members’ intent was to draw up a workable design for an extremely ambitious unmanned space probe, one capable of reaching a neighboring star system within fifty years. Moreover, they limited themselves to using only current and near-future technology, as this would allow the theories to be translated into practice one day if the concept proved feasible.

In order to reach even the nearest stars within the allotted fifty-year window, the thirteen scientists and engineers of the research group had a formidable task ahead of them. Their space probe would be required to accelerate to astonishing speeds, and it would need to weather the constant battering of particles from the soup of space debris known as the Interstellar Medium. In spite of these problems, in 1978 the organization presented a highly developed spaceship concept which may yet prove to be the model for future interstellar travel. It was called Project Daedalus.

→

Decades before Project Daedalus began, astronomer Peter van de Kamp began using photographic plates to measure extremely small variations in the position of one of our sun’s nearest astronomical neighbors: Barnard’s Star. In 1963 he announced that he had detected a perturbation in the star’s movement, a wobble imparted on a star due to the tug of orbiting planets. Because of this distinction, the relatively close star— only 5.9 lightyears away— was selected as the destination for the Interplanetary Society’s theoretical unmanned spaceship.

The project had three clearly stated guidelines:

The spacecraft must use current or near-future technology.
The spacecraft must reach its destination within a human lifetime.
The spacecraft must be designed to allow for a variety of target stars.

When the Society began their study, the fastest vehicle in existence was the Pioneer 10, a probe which was zipping through space at a brisk 51,810 kilometers per hour. Pioneer’s journey to Jupiter was to last over a year and a half, but if it were to travel to Bernard’s Star at such a speed, it would spend approximately 123,000 years in transit. Clearly the Daedalus would require an extraordinary propulsion system far beyond even the best technology of the time.

In order to accelerate sufficiently, the researchers envisioned the use of a two-stage nuclear pulse rocket. Similar to chemical rockets in basic principle, such rockets would create thrust by causing a very small explosions in a rapid series. Pellets comprised of deuterium and helium-3 would be bombarded by high-powered electron beams, thus triggering fusion and detonating the mass like a tiny nuclear bomb. These explosions would be repeated at a rate of two hundred and fifty per second, using a powerful magnetic field as the rocket’s nozzle.

Using this principle, the Daedalus’s first rocket stage would fire for two full years, consuming 46,000 tons of fuel to accelerate to about 76.6 million kilometers per hour. The Daedalus would then jettison the exhausted primary stage, shrugging off much of its size and weight as the second stage takes over. Just shy of four years after departure, the spaceship would expend the last of its fuel, and coast for the remaining distance at the ludicrous speed of 135 million kilometers per hour— about 1/8 of the speed of light. By way of comparison, a vehicle traveling at that velocity could reach Jupiter from Earth in under five hours, or reach New York City from Paris in 0.156 seconds.

Daedalus design, courtesy of Adrian Mann

Though the scant, slow-moving particles of the Interstellar Medium are seldom larger than grains of rice, the millions of tiny, high-speed impacts would have a sandblaster effect upon the Daedalus. To combat this erosion damage, the Society members incorporated a beryllium deflection dome on the nose of the probe. Beryllium is a very lightweight metal with excellent thermal conductivity, making it ideal for the task. In addition, the Daedalus would be escorted by its own protective particle cloud, which would precede the spaceship at the same extreme speed, sweeping most larger objects out of the path. Any damage which occurred in spite of the protection would be repaired by a small army of “wardens,” remote-controlled robots which serve the Daedalus master computer.

On approaching the halfway point, the Daedalus master computer would direct its pair of five-meter-wide optical telescopes towards the Barnardian System to take photographs to send back home. The massive, 40-meter-wide engine bell of the second stage would double as a radio dish, transmitting imagery and data towards our solar system— the relatively bright star directly behind the ship. About two years later— approximately twenty-seven years after the probe’s departure— the first close-up photos of Barnard’s Star would finally reach the Earth. These images would reveal the exact positions of any attendant planets, allowing mission control to select points of interest.

Several years before completing the fifty-year journey to the star, the master computer would arouse its slumbering robotic passengers, and assign each a route based on earlier photographic findings. These eighteen sub-probes would then spring into action, breaking away from the mothership and darting off to their destinations powered by independent ion drives. Their cameras, spectrometers, polarimeters, and other instruments would make as many pictures and readings as possible while flying past planets at high speeds. As the sub-probes chatter away by radio, all data would be relayed back to Earth using the powerful transmitter on the mothership. Naturally many instruments would be tuned to search for evidence of life-harboring climates. Slowing down or stopping would be impossible since the fuel for braking rockets would increase the mission’s weight budget too drastically, so the Daedalus and probes would have a relatively short time to make observations before zipping past the star system at over a million kilometers per hour.

Due to the Daedalus’s massive size and environmentally hazardous fuel, it would almost certainly need to be constructed in orbit if the project were ever undertaken. The Helium-3 component of its fuel is scarce on Earth, but it is thought to be abundant in Jupiter’s atmosphere. Therefore the Interplanetary Society suggested that the starship might first make a detour there in order to scoop up and store sufficient Helium-3 for the journey.

Rendered image of the Daedalus arrival, courtesy of Adrian Mann

More recent data indicates that there are in fact no planets orbiting Barnard’s Star, but the Daedalus design is flexible enough to apply to many other interstellar destinations. To this day, NASA considers the thirty-six year old research as a useful baseline study which addresses the problem somewhat effectively. The researchers at the British Interplanetary Society optimistically estimated that such a craft would be possible by the late 1990s, though they acknowledged that such a starship would still be prohibitively expensive without unprecedented international cooperation.

Technologies are gradually appearing and evolving which could one day bring Daedalus— or something like it— to fruition. But at some point in the 1980s, our culture’s when-and-how optimism was smothered by why, and respectable scientists were urged to shelve their absurd ambitions for more practical pursuits. I say let the sticks have their mud… I want a massive interstellar space probe.

This is quite a feat here! Wow. Although, unless they speed up the project and the vehicle, I’ll surely never witness anything of the kind. But for the sake of humanity and other earthly critters, I hope one day this fantasy can become true.

Perhaps I’m reverting back to my childhood here, but wouldn’t a person traveling that fast who came back to earth after 100 years witness some sort of skew in the space-time continuum and be a lot younger than those of us left behind?

Nice Alan. Nice. Got my fix.

Prince

Posted 14 December 2006 at 11:44 pm

Second!

Drakvil

Posted 15 December 2006 at 12:06 am

Minute! (wait, why are we naming the hands of clocks?)

Etonalife: yes, I do believe the theory is that as you approach the speed of light there is a time dilation effect, and the effect is supposed to become more pronounced the closer you come to the speed of light. Of course, since the people on Earth would experience the traveller’s journey as taking over 100 years, there wouldn’t be anyone left that would be in any position to tell.

If the ship were to stop at the other end, that would mean that an equal amount of time would have to be spent decelerating as accelerating, which would signifigantly increase the travel time to get there as well as the fuel and weight requirements. (how long would it take you to run 10 yards across a room and have to stop before hitting a wall as opposed to running across the room and out the door at the other end?) Good thing this probe idea calls for only robots to make the trip. Unless there is a planet there or something to live on I wouldn’t want to make that journey. It would be cool to make a trip to another star, but at the rate of one star system every 50 years I think I would run out of books to read.

With the robot probes, we would get a heck of a lot of information about thousands of star systems we couldn’t get otherwise… having a 5.9 light-year baseline for triangulation of distances to objects as opposed to the 2 AU (twice the distance from the Earth to the Sun) baseline we have now would increase our ability to identify the distances to objects a millionfold. Well, if we could decelerate an orbiting telescope in that system, that is. I wonder what the weight requirement would be for a secondary craft made just for decelerating a minute fraction of the large craft’s mass into an orbit about the star?

BarryW

Posted 15 December 2006 at 01:00 am

So they need Helium-3… there’s a story on Wired talking about the possibility of mining a large amount of Helium-3 on the Moon.

ballaerina

Posted 15 December 2006 at 01:02 am

Awesome article Alan, despite your work-induced sleep deprivation.

Ever since I started researching astronomy, I’ve been hoping they’d build some sort of device to visit other solar systems. Even if they didn’t find life, the accomplishment would be unbelievable. To think that we’ve come this far in such a short time – and then when you look at it in a broad light you realize we haven’t come far at all.

I remember reading a quote – maybe someone has heard it before and can tell me who to give credit to?
“If the universe is like an ocean, then humans have only just set foot on the beach.”

Dr. Evil

Posted 15 December 2006 at 01:31 am

I bought 80 metric tonnes of Helium 3 on Ebay… I was thinking of sharing but I just remembered my plans to build my own Death Star ( moon with laser). It shall be called the alan parsons project. *ok Mini me…Stop humping the Laser…Why dont you and the laser get a fricken room?*

Tyler

Posted 15 December 2006 at 01:40 am

Damn interesting! That’s about all I can say.

Silverhill

Posted 15 December 2006 at 01:44 am

etonalife said: “Perhaps I’m reverting back to my childhood here, but wouldn’t a person traveling that fast who came back to earth after 100 years witness some sort of skew in the space-time continuum and be a lot younger than those of us left behind?”

Drakvil said: “Etonalife: yes, I do believe the theory is that as you approach the speed of light there is a time dilation effect”

There is indeed a time-dilation effect, and not just in Einstein’s relativity theory–it is observable by experiment, such as has been done with atomic clocks. (One clock was flown around the world on a fast airplane, while another stayed in the lab as a reference. Upon return, the traveling clock was behind the stationary one in the amount predicted by theory.)

The amount of time-skew for a journey at only 0.125 c would not be great, however–a returning traveler would have experienced a reduction in rate of time of only about 1%. You have to get really close to c–close to 99%–to see large changes in time. (You have to expend ludicrously large amounts of energy to go that quickly, too!)

For an entertainingly done tale of a trip to Barnard’s Star, read Rocheworld by the late Dr. Robert Forward. In that story the star has planets, and life to boot, as the intrepid explorers from Earth discover. (They traveled by lightsail instead of a fusion-pulse drive; they also had completely committed themselves to the mission, because it was one-way.)

exsomnis

Posted 15 December 2006 at 01:47 am

The technology might be almost here, but I think it would probably take another 50 years or more before humanity is seriously ready to undertake such an abstract mission. Either that or we cure the world of all its flaws and imbalances first.

Let’s hope it doesn’t take another Cold War to get the Americans busy in space again. Although it seems inevitable that the US will have to face China some day, if either party becomes overly belligerent.

Wihtgar

Posted 15 December 2006 at 03:09 am

“But at some point in the 1980s, our culture’s when-and-how optimism was smothered by why”

Truer, sadder words were never writ.

Metryq

Posted 15 December 2006 at 04:55 am

Wihtgar said: “”But at some point in the 1980s, our culture’s when-and-how optimism was smothered by why”

Truer, sadder words were never writ.”

Jack McDevitt’s recently published ODYSSEY (part of the “Academy series,” although the books read well independently) features starflight within days, scientific expeditions, two extra-Solar colonies, and even extra-Solar tourism, yet the Academy is on the verge of being mothballed — starflight technology that was easy, rather than a Herculean effort, yet still a victim of ennui. It sounds very credible, considering public response to the later Apollo missions.

Ever since I started researching astronomy, I’ve been hoping they’d build some sort of device to visit other solar systems. Even if they didn’t find life, the accomplishment would be unbelievable. To think that we’ve come this far in such a short time – and then when you look at it in a broad light you realize we haven’t come far at all.

I remember reading a quote – maybe someone has heard it before and can tell me who to give credit to?
“If the universe is like an ocean, then humans have only just set foot on the beach.””

I looked on Quoteland.com and couldn’t find it, but I like it!! :)

HarleyHetz

Posted 15 December 2006 at 06:51 am

Oh yea, and I second (or third, or whatever number I am) the “awesome article Alan” comment!! :)

Radiatidon

Posted 15 December 2006 at 07:31 am

‘tis sad indeed when this opus of the adventurous spirit drowns in the wine of soured grapes. Curse the day from grace of which we hath fallen. So should we allow the free of the spirit to be bound by the weight of fear, of loathing? Or should we strive forth from the warmth of our caves to the great unknown seeking the unbounded joy that the adventure shall fill us with?

Throughout history humanity has always taken a step back to adventure. It took some major smooching for many of histories explorers to gather the funds to proceed. To fight against the mainstream of Nay-Sayers.

I have traveled the world and seen many wondrous things. Death has at times patted me on the back, yet did not invite me to follow. I have come face-to-face with a moray eel, laid upon by a Bengal tiger, and survived an attacked by a bull elk with nothing more than torn clothes, antler scratches, and bruises (was hiking through the woods when I entered a clearing where his herd was grazing. Sucker blindsided me. Broke my radio.)

In one comment I mentioned how I had visited the USSR during the cold war. Another poster stated that this was “dumb” of me. If I had not gone, what a glorious adventure I would have missed. The amazing people, fantastic sights, mouth-watering tastes, and outstanding beauty that I would never had experienced. True such a visit had risks, even possible death. Then again, so does walking out my front door. To live in fear is not to have lived at all. Is not life a quest of knowledge in all its forms, and yet a feast to be enjoyed.

Hopefully the undeniable spirit of adventure will flare once again and help push us off the crust into the void, and fulfill the dreams of our grandfathers.

Rinson Drei

Posted 15 December 2006 at 08:13 am

HarleyHetz said: “I remember reading a quote – maybe someone has heard it before and can tell me who to give credit to?

“If the universe is like an ocean, then humans have only just set foot on the beach.”””

Are you thinking of Isaac Newton?
“I do not know what I may appear to the world; but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.”
Isaac Newton (1642-1727)
In Brewster, Memoirs of Newton (1855), vol II, Ch. 27

Rinson Drei

Posted 15 December 2006 at 08:28 am

I agree with Stephen Hawking’s thesis that space exploration and colonization is necessary to secure the future of mankind. What if we are the only life in our galaxy? This is probable. If so, a mere burp from the sun or an insignificantly small meteor could easily wipe out all life. The more spread out we are, the harder it will be for the Berserkers to find us.

HarleyHetz

Posted 15 December 2006 at 09:05 am

Rinson Drei said: “Are you thinking of Isaac Newton?

“I do not know what I may appear to the world; but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.”
Isaac Newton (1642-1727)
In Brewster, Memoirs of Newton (1855), vol II, Ch. 27″

Uhm, acutally I was merely answering Ballerina, but I don’t think that’s the quote she was looking for. I too have heard or seen the one to which she refers, but I can’t recall the source. A cursory search on quoteland.com resulted in nothing, and I’ve not been able to find anything since, so maybe we are both imagining it?? Growing up just down the road from the cape, it seems to me that it was some astronaut that said it, but again, I could just be dreaming…I was a teenager in the ’70’s after all…

BrianTung

Posted 15 December 2006 at 11:07 am

HarleyHetz said: “I remember reading a quote – maybe someone has heard it before and can tell me who to give credit to?

“If the universe is like an ocean, then humans have only just set foot on the beach.”””

Not exactly the same, but in Cosmos, Carl Sagan said, “The surface of the Earth is the shore of the cosmic ocean. On this shore, we’ve learned most of what we know. Recently, we’ve waded a little way out, maybe ankle-deep, and the water seems inviting.” Someone may have melded that with Newton’s quote to yield the above.

grendel25

Posted 15 December 2006 at 11:32 am

“Slowing down or stopping would be impossible since the fuel for braking rockets would increase the mission’s weight budget too drastically, so the Daedalus and probes would have a relatively short time to make observations before zipping past the star system at over a million kilometers per hour.”

Has anyone read Arthur C. Clark’s “Rendezvous With Rama”? An alien spaceship whizzed past Earth on its way to to use the sun to slingshot itself to some unknown destination, and people were sent to explore as much of it as possible before it was lost back into the interstellar abyss. What might Daedalus inspire in whatever civilizations it might encounter on the way to its target or beyond?

BrianTung

Posted 15 December 2006 at 11:36 am

Incidentally, Carl Sagan also briefly described Project Daedalus later in the Cosmos series.

James

Posted 15 December 2006 at 12:27 pm

Pretty cool thought but I’m not sure of the advantages of such a mission at this point in our space program. We can’t even build a space station or keep pieces of foam from destroying our current space craft at this point, let alone build nuclear powered space probe to go 5 light years and send back transmissions. I think our limited funds would be better spent on project centered on better propulsion systems or Ways to keep Our Astronauts healthily on long journeys and a whole list of what I would consider higher priority items. But maybe that is short sighted of me.

As for the question Why smothering the optimism of how and when. I think “why” is a perfectly legitimate question to ask. If we were to plan on spending billions of dollars on X we should be able to ask why we would want to do X instead of Y. Especially if Y will make X, as well as other projects, faster better and more effective. I don’t believe asking why makes you a pessimist. I think it’s a sign of intelligence. And not asking why is a sign of foolishness.

AlexandreDumas

Posted 15 December 2006 at 12:37 pm

What ever happened to warp speed? Have we completely given up on this?

It would totally solve all the hoo-haa about excess weight and long flight times… Mr. Hawking, the ball’s in your court.

ConcernedCitizen

Posted 15 December 2006 at 01:17 pm

@James: I didn’t see it as saying that there is no place at all for “why,” only that the why-ers were such sticklers that they smothered the old optimism. It’s always necessary to ask “why,” but it’s not the only question. That’s just my perspective on it.

lockedout

Posted 15 December 2006 at 01:26 pm

oh boy was that a tasty article, still digesting it!

James

Posted 15 December 2006 at 02:12 pm

Maybe I’m wrong but the implication was it may not be practical or serve need or purpose in our current space program but it would be really cool. The attitude of how and when was a product of direct competition between the US and the USSR the optimism was pride over beating the commies. We still asked why but the answer was “we can’t let Russians get there first”. For the power brokers funding the space race had very little to do with scientific curiosity. Whatever it reasons I am grad we did it and I hope we continue.

James said: “I think “why” is a perfectly legitimate question to ask. If we were to plan on spending billions of dollars on X we should be able to ask why we would want to do X instead of Y. Especially if Y will make X, as well as other projects, faster better and more effective. I don’t believe asking why makes you a pessimist. I think it’s a sign of intelligence. And not asking why is a sign of foolishness.”

Agreed. The problem is that, frequently, the “why-ers” don’t want to compare X to Y — they want to scuttle X in favor of Y. For example, some of those who advocate cutting back on the space program so as to spend more to reduce poverty refuse to weigh the benefits of exploration to the benefits of reducing poverty. They simply wave their hands and talk about saving lives — the tacit argument being “value of life = infinity” therefore comparison is not only impossible but reveals an inhumane callousness on the part of the questioner.

And thanks for pointing out the gas-giant problem…. in an earlier revision “Jupiter” appeared twice in the paragraph so I had changed the second to “gas giant” to avoid repetition. It’s fixed now.

SparkyTWP

Posted 15 December 2006 at 03:00 pm

AntEconomist said: “Agreed. The problem is that, frequently, the “why-ers” don’t want to compare X to Y — they want to scuttle X in favor of Y. For example, some of those who advocate cutting back on the space program so as to spend more to reduce poverty refuse to weigh the benefits of exploration to the benefits of reducing poverty. They simply wave their hands and talk about saving lives — the tacit argument being “value of life = infinity” therefore comparison is not only impossible but reveals an inhumane callousness on the part of the questioner.”

I think you hit the point exactly. Frequently people look at the space program and don’t see anything useful coming out of it. They don’t realize that most of the useful technology is not obvious at first. NASA was a huge boom to materials and aerial research. We wouldn’t have things like satellite communications or GPS. Even if nothing is gained except for knowledge of a far-off world, I think it would still be worth it given that the operating costs for NASA are far lower than other less-successful government programs.

I sometimes wonder if people criticized the funding of Columbus’ expedition because all there was to gain was some spices and poor people could’ve used the money instead.

labouton

Posted 15 December 2006 at 03:40 pm

Another great article but I really wonder if we’re mature enough to even think about taking our warring nature to other planets. It’s my understand that astronauts have to go through rigorous testing to ensure that they are capable of co-habitation for even a short period of time. Now imagine being locked in a closet with your love one for 50 years. Not a pretty picture:)

Secret Ninja

Posted 15 December 2006 at 04:35 pm

Drakvil said: “I wonder what the weight requirement would be for a secondary craft made just for decelerating a minute fraction of the large craft’s mass into an orbit about the star?”

Well, F=ma, so it would be possible to increase the amount of initial fuel to accelerate the larger mass required to decelerate the smaller mass, as a smaller force would be required to decelerate the less massive portion that would want to be slowed.
Unless I’m an idiot, which I’ve been called a few times before.

Illustrator

Posted 15 December 2006 at 11:33 pm

ballaerina said:
I remember reading a quote – maybe someone has heard it before and can tell me who to give credit to?

“If the universe is like an ocean, then humans have only just set foot on the beach.””

I think we’re only beginning to smell the salty air and we’re trying to find the beach where
a hidden treaure awaits containing the equations both in physics & ecomomics
to make such an endeavor possible, but that’s just me, great article.

And if we are the only life in the galaxy, that’s a lot of waisted real estate.

Silverhill

Posted 15 December 2006 at 11:35 pm

Secret Ninja said: “Well, F=ma, so it would be possible to increase the amount of initial fuel to accelerate the larger mass required to decelerate the smaller mass…”

Secret Ninja said: “Well, F=ma, so it would be possible to increase the amount of initial fuel to accelerate the larger mass required to decelerate the smaller mass, as a smaller force would be required to decelerate the less massive portion that would want to be slowed.”

What you both obviously don’t know is that mass increases with speed. This too is consequence of Einstein’s special theory of relativity. F=ma stays true, but m increases. The Formula for m with great velocities is:

m=M/sqrt(1-(v/c)^2)
M is the massfor the object at rest. v is the velocity. c is light speed.
If v=0, then m=M, this is what you normally expirience. But if v increases to greatly, in this case to v=c/8, then m=M * 1.069 , that means the mass has increased 6,9 % already. At the thousands of tons of this ship, this plays a big role. So increased payload is very expensive.

Drakvil said: “I wonder what the weight requirement would be for a secondary craft made just for decelerating a minute fraction of the large craft’s mass into an orbit about the star?”

I think if this thing is built, we should definately seek to put some kind of sattelite into this star system. It is possible for a small satellite to be slowed down enough to be trapped in Barnard’s Star’s gravity. The small craft with the braking engines could part from the main vessel about half way through and begin braking for the rest of the trip. It will arrive much later than the first high speed probes. But this is an advantage, because the system will already be scouted, so the late arriver can be put to best use. The only problem is, that the late probe cannot use the mothership as a relay to earth, so it has to have a sufficently big antenna.

The late satellite doesn’t even have to travel at all with the mothership. It could fly on its own the whole way. This wouldn’t really make a difference. It could even start its jouney before the fast moving ship.

Bolens

Posted 16 December 2006 at 07:23 am

I agree, jokkel. My intergalactic transport can never be fully loaded to legal specs because of that very theorem in practice. If I don’t keep it, say 5-8% under max, the ship’s safety sensors won’t allow me to initiate the hyperdrive. Or even calculate it on the console, for that matter. Which is fine, really, because I would rather have that over the messiness of a ripped-apart ship.

By the way, never, never go to a mining colony to steal a beryllium sphere.

ballaerina

Posted 16 December 2006 at 09:57 am

BrianTung said: “Not exactly the same, but in Cosmos, Carl Sagan said, “The surface of the Earth is the shore of the cosmic ocean. On this shore, we’ve learned most of what we know. Recently, we’ve waded a little way out, maybe ankle-deep, and the water seems inviting.” Someone may have melded that with Newton’s quote to yield the above.”

I think this is close to the quote I had in mind. My physics teacher was the one who originally quoted it for me, and he might have been paraphrasing.
I like the Issac Newton quote, too, though.

Misfit

Posted 16 December 2006 at 01:42 pm

Alan, you’ve done it again!

There is something more romantic than I can imagine about that last picture…

T-mizzle

Posted 16 December 2006 at 04:07 pm

Hmmm… Fascinating, quite interesting indeed.

—

! (.)(.)-BOOB ALERT! !

smokefoot

Posted 16 December 2006 at 04:18 pm

The Starwisp probe is a proposed lightweight intersteller probe which is driven by microwaves transmitted from earth orbit. It is much more practical from a cost standpoint, and the same transmitter can send multiple cheap probes out. A simular option uses lasers and lightsails to drive probes.

I got this from _Indistinguishable from Magic_ by Robert Forward (mentioned by other posters for another book). This book covers what may be possible with technology some day, and is full of ideas which would make good Damn Interesting articles!

Comments on other comments: We currently have no way to do Warp drive – the only way we know to warp space is with gravity, and the only way to create gravity is with huge amounts of matter.

Dr. Evil

Posted 16 December 2006 at 05:14 pm

Radar Operator: [Noticing Dr. Evil’s spaceship on radar] Colonel, you better have a look at this radar.

Colonel: What is it, son?
Radar Operator: I don’t know, sir, but it looks like a giant…
Jet Pilot: Dick. Dick, take a look out of starboard.
Co-Pilot: Oh my God, it looks like a huge…
Bird-Watching Woman: Pecker.
Bird-Watching Man: [raising binoculars] Ooh, Where?
Bird-Watching Woman: Over there. What sort of bird is that? Wait, it’s not a woodpecker, it looks like someone’s…
Army Sergeant: Privates! We have reports of an unidentified flying object. It has a long, smooth shaft, complete with…
Baseball Umpire: Two balls.
[looking up from game]
Baseball Umpire: What is that. It looks just like an enormous…
Chinese Teacher: Wang. pay attention.
Wang: I was distracted by that giant flying…
Musician: Willie.
Willie Nelson: Yeah?
Musician: What’s that?
Willie Nelson: [squints] Well, that looks like a huge…
Colonel: Johnson!
Radar Operator: Yes, sir?
Colonel: Get on the horn to British Intelligence and let them know about this.

zappedpyramid

Posted 16 December 2006 at 07:43 pm

“Their space probe would be required to accelerate to astonishing speeds, and it would need to weather the constant battering of particles from the soup of space debris known as the Interstellar Medium. ”
Actually, this is not a problem, it is a solution.
If the ship were to generate a magnetic field, much like that observed at the North and South poles of our planet, the Daedalus would have an effective barrier against the interstellar medium.
Subatomic particles would be swept up by the field and could be collected at the polar anode and cathode. Furthermore, as the spaceship gathers speed, the magnetic magnopause expands, allowing the ship to sweep aside the dangerous dust and grains. Just a thought.

Silverhill

Posted 16 December 2006 at 10:59 pm

jokkel said: “What you both obviously don’t know is that mass increases with speed. This too is consequence of Einstein’s special theory of relativity. F=ma stays true, but m increases. The Formula for m with great velocities is:

m=M/sqrt(1-(v/c)^2)

M is the massfor the object at rest. v is the velocity. c is light speed.

If v=0, then m=M, this is what you normally expirience. But if v increases to greatly, in this case to v=c/8, then m=M * 1.069 , that means the mass has increased 6,9 % already.”

Don’t be so quick to say what someone “obviously” doesn’t know, jokkel. I “obviously” was already acquainted with the Lorentz transformation when I made my approximate calculation w.r.t. time dilation above. Your calculation is a bit off, however–at v=0.125 c, gamma=1.008; you don’t get gamma=1.069 unless v=0.35 c. The energy needed to get to 0.35 c is much greater than Daedalus could achieve as designed.

Relativistically yours, Silverhill

Metryq

Posted 17 December 2006 at 04:56 am

zappedpyramid said: “If the ship were to generate a magnetic field, much like that observed at the North and South poles of our planet, the Daedalus would have an effective barrier against the interstellar medium.”

The Bussard Ramjet would use such a magnetic field. Originally, it was thought the design could accelerate asymptotically closer and closer to the speed of light, however later studies showed that the magnetic scoop would impede the ship after a certain point. Also, there’s still the problem of non-ionized particles. Yes, I’ve read about lasers being used to deal with such particles, but missing even one could be problematic. I’d rather have the ablative shield up front.

Arthur C. Clarke described a starship (The Songs of Distant Earth ?) with an ablative shield made of ice. The interlocking ice panels could be renewed at each planetfall.

aemann2

Posted 17 December 2006 at 09:22 am

Hi all,

I’m the guy who did the illustrations accompanying the article, and I’ve accumulated a huge amount of info on it since I first came across the project many years ago. I do some work for a company called Reaction Engines in the UK (www.reactionengines.co.uk), one of the directors just happens to be Alan Bond – one of the designers of the Daedalus probe. I was always curious about the use of Beryllium for the erosion shield – he said it was because it was a) the second lightest metal and b) has the highest specific heat of vapourisation, making it ideal for an erosion shield. The particle cloud ahead of the ship was to be maintained by small vehicles known as ‘Dust Bugs’, though the dust woul be more like cigarette smoke.

The Bussard Ramjet is interesting. In ‘Entering Space’ by Robert Zubrin, it’s clear that the magnetic drag created by any field large enough to capture enough hydrogen for fuel would create more drag than the engine would produce thrust – which raises a thought; why not use the magnetic field braking effect to slow the probe down? Even if the speed wasn’t reduced to a point enabling the probe to go into orbit, it might provide more time to investigate the target system.

When I was a youngster, I gathered up the necessary math skills and calculated the ship-board travel times to the stars if one had an engine capable of indefinite 1g acceleration. And, no, we don’t have such an engine but there are hints (the Casimir Effect comes to mind) that such a thing may not be impossible. I don’t remember exactly the results, and I ain’t gonna do it again, but it was pretty startling. Alpha Centauri was about 6 years away. Anything within 100 light-years was about 10 years away. The center of the galaxy was only about 20 years away. I’ve had people tell me that no one would make a voyage that had so much time go by outside the relativistic envelope. I’d go in a second:-)

student

Posted 17 December 2006 at 05:41 pm

Silverhill said: “There is indeed a time-dilation effect, and not just in Einstein’s relativity theory–it is observable by experiment, such as has been done with atomic clocks. (One clock was flown around the world on a fast airplane, while another stayed in the lab as a reference. Upon return, the traveling clock was behind the stationary one in the amount predicted by theory.)

The amount of time-skew for a journey at only 0.125 c would not be great, however–a returning traveler would have experienced a reduction in rate of time of only about 1%. You have to get really close to c–close to 99%–to see large changes in time. (You have to expend ludicrously large amounts of energy to go that quickly, too!)

For an entertainingly done tale of a trip to Barnard’s Star, read Rocheworld by the late Dr. Robert Forward. In that story the star has planets, and life to boot, as the intrepid explorers from Earth discover. (They traveled by lightsail instead of a fusion-pulse drive; they also had completely committed themselves to the mission, because it was one-way.)”

I got a relativity question: If the closer you get to the speed of light the more energy you have expend to accelerate because you become more massive or something, wouldn’t the travelers be able to detect this and thereby know that they were more massive and is that not a contradiction — they shouldn’t be able to detect their own increase in mass?

aemann2

Posted 17 December 2006 at 06:21 pm

I think that for the travellers everything would appear normal – time would pass normally, and likewise the mass of objects within their frame of reference would appear unchanged too. Thats Relativity for you – everything is relative – how the universe looks depends on where you are, or how fast you’re moving. Though it does raise another interesting question – if an outside observer could detect the increase in mass of an object approaching the speed of light, would the occupants of the craft be able to detect a corresponding decrease in mass of the rest of the universe? And if an object travelling at precisely c had infinite mass, would that mean from their point of view the mass of the rest of the universe would be zero?

adastra

Posted 18 December 2006 at 11:50 am

Here’s an interesting one. A photon, by definition, travels at the speed of light. A photon is not without mass. How come it’s mass isn’t infinite? And does time stand still for that photon? Is it leaving a star’s surface and hitting your eyeball at the same time?

Silverhill

Posted 18 December 2006 at 07:45 pm

aemann2 said: “I think that for the travellers everything would appear normal – time would pass normally, and likewise the mass of objects within their frame of reference would appear unchanged too.

Indeed so.

“Though it does raise another interesting question – if an outside observer could detect the increase in mass of an object approaching the speed of light, would the occupants of the craft be able to detect a corresponding decrease in mass of the rest of the universe?

They would be able to detect an increase in the observed mass of the universe, relative to them. The proportional mass increase would be just the same as would be detected for them.

“And if an object travelling at precisely c had infinite mass, would that mean from their point of view the mass of the rest of the universe would be zero?”

Assuming for the purpose of illustration that a nonzero-rest-mass object could travel at c, then the rest of the universe would appear also to be traveling at c and its mass would appear to be infinite also.

adastra said: “Here’s an interesting one. A photon, by definition, travels at the speed of light. A photon is not without mass. How come its mass isn’t infinite? And does time stand still for that photon? Is it leaving a star’s surface and hitting your eyeball at the same time?”

A photon is not considered to have mass — rest mass, that is, since it cannot be at rest and still be a photon. It has momentum, however, that can be transferred to an object that absorbs or reflects the photon.

Since photons do not have mass in the usual sense, they don’t show a mass difference due to their speed. Time dilation still applies, however, so that the universe does appear to be timeless to a photon. From its point of view, its emission and absorption are indeed simultaneous.

spikyface

Posted 19 December 2006 at 09:51 am

Whilst it sounds like a great idea has anyone ever thought that maybe there are Inhibitors waiting for us out there?

This discussion is one more reason why I would love to stand all the members of the Congress back in the 70s up against the wall and shoot them. Go to any major NASA site and you will see one or more Saturn V’s. Those are real rockets, not models. They were all supposed to be launched. We had a space station in the 70s. One rocket launch would have saved it for another 4 years or more. They preferred to build more housing projects, which we are now paying to knock down.
Columbia blew up because Congress was too cheap to appropriate money to ship the booster rockets by ship from California to Florida, so they put in the joints to make them land-transportable. Ever wonder why the uproar calmed down so quickly, and why no one went to jail?

As for space flight, we are still stuck with a failed design that was supposed to be retired a decade ago. It never came close to the concept of a “space truck”, and has been more trouble and expense than if we had just used a bunch of Titan-4’s instead. THAT was a truck. NASA is just another collection of bureaucrats; the original ‘fire in the belly’ Mercury-Gemini-Apollo crowd is retired after seeing their dreams die. The next people to set foot on the moon will be Chinese. They, at least, have scientific drive and national pride. Ours seems to be dead.

aemann2

Posted 21 December 2006 at 06:35 pm

Here here… the Apollo programme was scheduled to continue into the mid-20’s, and all the hardware was built and ready to go. The Shuttle was supposed to be part of the 3-part programme – shuttle, space station, mission to Mars. Mars and Space station got cancelled, leaving the shuttle with nowhere to go. The US military had a large hand in it’s design – the wanted to be able to launch into polar orbit from Vandenburg so it had to have cross-range capability to land, hence the big, useless wings that have to be carried to orbit and back, and are only useful for the final 10 minutes. Sure, it’s a glider – it glides about as well as a brick. I’m afraid the whole shuttle adventure has proved to be a very costly dead end, which leads us to the new “Constellation” programme. What have we got – Apollo on Steroids! It’ll even use J-2 engines which are Apollo vintage.
The Russians have just announced a new space exploration programme, the Chinese have a serious programme, and even India is talking about it’s own manned space programme. It’s a pity that all the nay-sayers and “back to the caves” groups have such influence, or the US might have a decent, well-funded programme. None of the money spent on NASA gets spent in space – it’s all real dollars, spent right here on Earth, supporting many thousands of families, businesses and suppliers. I read somewhere that at the height of the Apollo programme, the US was spending more on chewing gum, dog food, or pornography! Wouldn’t those three *ahem* “worthwhile” activities make a better target for the “spend the money on curing poverty/disease/hunger” arguments?

adastra

Posted 22 December 2006 at 11:10 am

Silverhill said: “Indeed so.

A photon is not considered to have mass — rest mass, that is, since it cannot be at rest and still be a photon. It has momentum, however, that can be transferred to an object that absorbs or reflects the photon.

the universe does appear to be timeless to a photon. From its point of view, its emission and absorption are indeed simultaneous.

Thanks for that. I’ve tried to express that view to several, scientifically literate friends , who all said I was nuts. How could that be? The ramifications are kinda interesting. All the light in the universerse, and, I guess, every other electromagnetic phenomenen that travels at the speed of light, is produced and recieved at the same time.

Now, that is Damn Interesting.

Drakvil

Posted 22 December 2006 at 12:28 pm

I just noticed that in the images of the proposed ship the ablative shield’s diameter (as seen from the front) is not as large as the diameter of the ship. This seems to relegate the outer portions of the ship to being worn away during the journey.

Some would argue that the center of the shield will absorb almost all of the punishment, but that would be true only if the ship was a target and the particles were being aimed at it as such… most of the bullets striking closer towards the middle. Since the particles are for the most part stationary and (effectively for navigation, not for actual use) uniformly distributed, that would indicate that the outer portions of the ship (roughly 20% of the cross sectional area) would suffer 100% of the damage destined for them whilst the other (roughly) 80% would receive none.

Or it could just be artistic license to make a cooler looking spaceship. After all – if it doesn’t look cool, what’s the use of having a spaceship?

aemann2

Posted 22 December 2006 at 06:47 pm

It’s because it looks cool – I admit it! That and the thing being based on the original BIS drawings… I can try to find out what the reasoning was behind that, but it may take a little time.
Regarding the photon emission/absorbtion thing – I seem to recall a theory from Richard Feynman, which stated that actually the entire universe is composed of just one single particle, which zigzags back and forward through all of space and time simultaneously, and in an infinite variety of forms, effectively weaving the universe and everything in it – something to do with “Sum over histories” as I recall. Of course, my recall may be deeply flawed so feel free to expand/clarify/contradict. Feynman – now there was a damn interesting guy!

adastra

Posted 25 December 2006 at 09:32 pm

Feynman – now there was a damn interesting guy!

Aero

Posted 30 December 2006 at 11:04 pm

Prince said: “Second!”

Last!(For now until someone posts)

This reminds me of a short sci fi story about a colony who set out to “live” on a ship for however long possible because earth was attacked by a terrible disease. They were self supporting. They had seperate groups, in which some people became mad. Eventually, after 1,500 years, a ship came up to them and told them the disease had ended and that they could come back hom. Well…
back on topic
This was pretty interesting, but makes me think that this isn’t going to happen for a very, very long time. I could be wrong though.

glhayman

Posted 23 January 2007 at 08:34 pm

The deadalus project is ridiculous. What happens if you need to avoid unseen obstacles, what about the huge impact forces on the ship and crew, what about the problems of getting a huge heavy radiation sheild into space using conventional means, what about the long term exposure to said radiation on the crew, what about the massive pollution caused by releasing all this radiation into space not to mention its effect on any future travellers following the same course????

The following website provides a much safer, simpler, cheaper, more viable, controllable and evironmentally friendly solution to the problems of travelling extreme distances in space. It is based on known science and provides numerous substantiating links and evidence to support the claims made. All that is required is serious research and investment.

AntEconomist said: “Agreed. The problem is that, frequently, the “why-ers” don’t want to compare X to Y — they want to scuttle X in favor of Y. For example, some of those who advocate cutting back on the space program so as to spend more to reduce poverty refuse to weigh the benefits of exploration to the benefits of reducing poverty. They simply wave their hands and talk about saving lives — the tacit argument being “value of life = infinity” therefore comparison is not only impossible but reveals an inhumane callousness on the part of the questioner.”

The real problem is that people say “oh, we can’t do that, we need to spend that on defeating poverty” and then say “oh we can’t spend that on poor people because I need a raise”. I know that sounds petty, but I’m still hungover…

glhayman

Posted 31 January 2007 at 11:30 am

Sorry the website was down for yearend and an overhaul. Please try again to see a new method for exploring deep space.

Well, you see, if you had actually read the article you would have seen that it is unmanned, so most of the arguments you’ve made agaisnt Daedalus aren’t really relevent. Also, the radiation given off by the engine would be miniscule compared to that which is already present in space and there wouldn’t be any massive impact forces as all of the tiny particle impacts would be absorbed by the beryllium deflection dome, and later by the particles themselves as they built up infront of the craft.

glhayman

Posted 19 April 2007 at 05:28 pm

I did miss the fact it was unmanned. Still it isn’t very manauverable or practicle. Presently feasible sure but what is the point of developing such a exploration method if we could never actually use it to get there ourselves?

MarshyMarsh

Posted 14 July 2007 at 04:16 am

glhayman, you don’t suddenly make a giant ‘noahs’ ark of space. During the space race, they didn’t all decide to visit the moon straight away, you have to take things one step at a time, from a simple ‘sputnik’ to a huge cloud of satellites orbiting the earth. It will also be useful, as in the future, this will be consdiered a ‘cheap’ design, good for research. Send this little guy to a star system first, see if it is hospitable (we are talking a long time into the future here), and then send manned missions (a very long time, seeing as not many people are sure if the moon landings where real).

Falco Peregrinus

Posted 16 July 2007 at 02:31 pm

Here’s an idea.

If the nuclear pulse rocket’s nozzle is magnetic couldn’t it, keeping in mind this is taking into account today’s near-future technology, be used to create a secondary interstellar debris shield and, this is the near-future stuff, could this be used, in conjunction with a layer of magnetically suspended plasma (currently a 1 or 2 inch “force field”/window using plasma and magnetic fields has been made somewhere, no idea were I saw it), along with extra thermal shielding, and the beryllium shield as mentioned in the article be used to, in a manner similar to the way the Mars Reconnaissance Orbiter used aerobraking to slow down, protect the probe so that it could use the destination star’s corona/atmosphere to slow down and perhaps if it could be figured out ahead of time or planned in route to use the native planets’ atmospheres to slow down so it could like get an anti-sling shot effect as well or in conjunction with “solarbraking”, yes I made that word up (probably), technique. Also, although I don’t know of any mechanism/technique that does this, the probe could perhaps utilize the principles of gravitationally slinging things to slow it down for interstellar insertion, maybe. It also would be neat to know if a probe could use the sling-shot effect in our solar system as many times as possible, whizzing in a tangled web of acceleration to rob as much speed as possible, over the course of many years probably, before heading out. All of this stuff, of course, requires veeeery accurate measurements in order for any of it to work which would be damn near impossible to do here and possibly just as much so in route.

I loves me some commas!

shenk14

Posted 04 October 2007 at 01:45 pm

“I want a massive interstellar space probe.”

that really did make my day!

dacoobob

Posted 26 November 2007 at 08:03 pm

When they said “nuclear pulse rocket” I immediately thought of Project Archangel (a spacecraft powered by “conventional” H-bombs, also proposed in the seventies). DI should do an article on that one.

dacoobob

Posted 26 November 2007 at 08:07 pm

Do’h, I meant Project Orion. Sorry.

BrianMcKinnon

Posted 24 September 2008 at 09:46 am

So, I’m well over a year late for this, but maybe someone will see this and call me profoundly retarded like I probably am.

Well.. does mass matter in space flight? I would think the only time mass mattered would be when trying to break out of gravity. after that wouldn’t any amount of force accelerate any mass equally?

BrianMcKinnon

Posted 24 September 2008 at 09:49 am

And from this reading, I gather I’m correct in thinking that you will keep moving in space after, say, 5 seconds of acceleration. Until 5 seconds of equal thrust are used in the opposite direction?

Mirage_GSM

Posted 07 October 2008 at 04:28 am

@Brian:
Yes, 5 seconds of thrust in space with no other gravitational forces will get a ship moving – regardless of its mass – until it is stopped by an equal amount of thrust in the opposite direction (or friction with the occasional molecule floating about in space). Even a squirtgun would get a spaceship moving.
The problem is the amount of velocity you can impart on the ship.
The equation you should be looking at is “F = m * a” (Force equals mass times acceleration).
So the acceleration you get for your ship is equal to the force of the thrust divided by the ship’s mass. So the bigger the mass is, the smaller the acceleration will be and you will only get that acceleration for the duration you apply the force.
to achieve the velocities needed to get to another star, you need to apply the force continuously for (in this case) several years, and to accelerate an object with a mass of more than 50.000 tons you’d have to apply a whole lot of force.
So in reply to your original question: Yes, mass DOES matter ;-)

glhayman

Posted 17 April 2009 at 04:09 pm

The problem with Deadalus and Orion is the time involved, and a complete lack of understanding of the possible dangers of interstellar space. At the velocities they are proposing the interstellar dust alone would disintigrate the craft in a relatively short period of time. It essentially goes straight, really fast, and depends on there being no requirement for a major course correction.

Furthermore, the technology I introduce is relatively simple, although new, and chances are with moderate research we could develop a probe which could beat deadalus anywhere by a longshot. Plus it could return, is manouverable, protects itself through its own mode of propulsion and does not require dangerously radioactive materials.

We could spend millions developing Deadalus, send it out, and with less money and time build a completely new type of probe which would beat deadalus to its destination, even if launched years later.

Just really bugs me that with all our potential all we can come up with is a nuclear missle.